Endoscopic operations for removing diseased tissue are known. To this end, an endoscope and one or more access means, for example trocars, are introduced into the body cavity in question and the affected tissue detached, for example by means of high-frequency surgery. If the pieces of tissue are small pieces of tissue, they can be removed from the body cavity through one of the access means. However, if the detached pieces of tissue are too large for removal through an access means, they have to be cut up prior to removal. This can be carried out for example by means of what is known as a morcellator, which has a rotating blade and a working duct passing through it. In this way, smaller pieces can be cut off large pieces of tissue and removed from the body cavity. In the case of infectious tissue, however, there is the risk of the disease spreading during the cutting up of the pieces of tissue, simply because tiny remnants of diseased tissue could remain in the body.
In order to prevent the spread of a disease, it is sensible to place a detached infectious piece of tissue in an extraction bag, also known as an endobag, to guide the open end of the latter through the access duct, and to morcellate the diseased piece of tissue in the extraction bag. This ensures that no remnants of infectious tissue remain in the body cavity. However, during endoscopic operations, body cavities are generally insufflated, i.e. a gas (nitrogen, carbon dioxide, helium etc.) is blown in in order to expand the body cavity. As a result, the surgeon is provided with more operating space.
However, as a result of the positive pressure within the body cavity, the extraction bag containing the detached diseased tissue is compressed so much that it is difficult if not impossible to detach the small pieces of tissue with the morcellator and remove them. In addition, there is the risk of the rotating blade of the morcellator cutting the extraction bag itself and parts of the infectious tissue passing back into the body cavity.
Therefore, the object of the invention can be considered that of specifying an access system for endoscopic operations, by way of which an extraction bag, in spite of the positive pressure in a body cavity, is expanded to such an extent that the tissue located in the extraction bag can be cut up without risk by means of a morcellator and removed.
This object is achieved by an access system for endoscopic operations according to independent claims 1, 8 and 13. Advantageous developments are the subject matter of the dependent claims.